I have a K-x with the stock lense, and I am looking at some mega zoom lenses.. As I am new and don't want to shell out a lot of bucks to fool around with my new toy just yet, I've been looking on eBay and B&H and other sites for a used lense in good shape. I've noticed quite a few of the less expensive lenses are older film era AF zoom lenses. The reviews for the ones I've been looking seem positive. So outside of the obvious...the lense will be some years old, is there a major downside to using a film era lense on a DSLR?

The "upside" of using a Pentax is having the compatibility with 30 (or so) year-old film era lenses on any K-Body DSLR. I don’t think there really is a downside of using film era lenses on new bodies other than film era lenses will have “old” coatings that may not be as good as the ones used on lenses of today. You do want to be careful about old third-party lenses which may have the infamous “Ricoh Pin” and can get stuck on a DSLR body.

When you say “mega-zoom” did you mean lenses in the 200mm-300mm range? Or all-in-one zooms..i.e.18-250mm / 28-300mm? In the 300mm range I’d recommend looking at the DA or DAL 55-300. Identical optics but with the latter having a plastic mount, no hood, no quick-shift and can be found for ~$180 dollars or less in the used market. I believe there is one right now in the market place. Cheers!

Honestly, one of the joys (?) of the Pentax system is that you can use those older (and many times cheaper) lenses quite effectively. Depending on the lens, there can be a short learning curve (for example manual focus, or stop down metering on pre A lenses) but it's actually quite easy and there are lots of threads on this site about how to do all of that. If you stick to older film AF lenses you really shouldn't have to worry about any of that as they will work just like the current DA series of lenses. One side affect of doing this is that you 'might' consider dabbling in film again(?) and pick up an old film body + lens to play with. Have fun.

The "upside" of using a Pentax is having the compatibility with 30 (or so) year-old film era lenses on any K-Body DSLR. I don’t think there really is a downside of using film era lenses on new bodies other than film era lenses will have “old” coatings that may not be as good as the ones used on lenses of today. You do want to be careful about old third-party lenses which may have the infamous “Ricoh Pin” and can get stuck on a DSLR body.

When you say “mega-zoom” did you mean lenses in the 200mm-300mm range? Or all-in-one zooms..i.e.18-250mm / 28-300mm? In the 300mm range I’d recommend looking at the DA or DAL 55-300. Identical optics but with the latter having a plastic mount, no hood, no quick-shift and can be found for ~$180 dollars or less in the used market. I believe there is one right now in the market place. Cheers!

Thanks for the description. The one I was looking at was an older Pentax Takumar lens 70-200. The reviews on here were pretty good and I can probably get it for under $50. Does it have the Ricoh Pin? I have no idea. The description says it's compatible with K-mount lenses, and as the A setting as described above.

Eventually I'll buy something newer and better and probably more expensive. But I don't want to lay out a lot of cash and then find I don't like it.

I have a K-x with the stock lense, and I am looking at some mega zoom lenses.. As I am new and don't want to shell out a lot of bucks to fool around with my new toy just yet, I've been looking on eBay and B&H and other sites for a used lense in good shape. I've noticed quite a few of the less expensive lenses are older film era AF zoom lenses. The reviews for the ones I've been looking seem positive. So outside of the obvious...the lense will be some years old, is there a major downside to using a film era lense on a DSLR?

I will echo some of the cautions of a very small group of "film era" lenses designed for Ricoh camera systems. The lenses can usually be identified with P-KR on the aperture ring. For more history and explanation just search this site or Google "Stuck Lens/Ricoh Pin".

Many on the forum will say there is no real downside to using older lenses. Many even have a preference towards older, "film era" lenses. Photography can be just as rewarding regardless of what lens you are using.

Thanks for the description. The one I was looking at was an older Pentax Takumar lens 70-200. The reviews on here were pretty good and I can probably get it for under $50. Does it have the Ricoh Pin? I have no idea. The description says it's compatible with K-mount lenses, and as the A setting as described above.

I'll assume it's the Takumar-A 70-200, which is a K-mount lens -- not as highly regarded as some others, but certainly worth up to US$50. (Well, mine was US$8 but that was a couple years ago!) No, it has no Ricoh pin. Yes, it will work fine on your dSLR. Because it is not SMC (Super Multi Coated) it won't have the flare resistance of pricier lenses, so you'll want to use a hood and not aim directly into bright lights.

I don't find a downside to using older lenses -- of the ~220 in my current stash, only about 5 or 6 were bought new. I love getting superior optics for a pittance. The closest to a 'downside' to using lenses that aren't AF or A-type (lacking electrical contacts on the lens base) is that they may take a bit more work than such Auto lenses, in terms of metering and stopping-down. But they can still deliver outstanding images.

So outside of the obvious...the lense will be some years old, is there a major downside to using a film era lense on a DSLR?

Yes.

You'll sit and giggle so much about how much money you saved over buying new that friends who aren't aware may think you've gone mad and have you sent away for psychiatric evaluation. Purchasing old lenses is also habit forming.

(The lenses I use every day on my DSLR came from the late 1950s, cost me practically nothing, and work splendidly).

Thanks for the description. The one I was looking at was an older Pentax Takumar lens 70-200. The reviews on here were pretty good and I can probably get it for under $50. Does it have the Ricoh Pin? I have no idea. The description says it's compatible with K-mount lenses, and as the A setting as described above.

No genuine Pentax lens (Takumar, Super Takumar, SMC Takumar, Takumar (Bayonet), FA, FA-J, DFA) will have the dreaded Ricoh pin. Be careful on eBay, though. Some less knowlegdeable or scrupulous sellers will say a lens is a Pentax lens, when it really is a third-party lens made to FIT a Pentax camera.

Also, no autofocus lens, whether genuine Pentax or third-party, will have the Ricoh pin, either.

The good news is that the Ricoh pin is fairly easy to deal with, it you do it before you get it stuck on your camera.

Also be careful of *some* (not all) Vivitar lenses. There is a shield that protects the aperture actuating lever. This is present on all k-mount lenses, but on some Vivitar lenses, it is longer than necessary and bumps up against the HSM power contacts on Pentax dslrs. This, too is relatively easy to modify or remove altogether.

You guys are the best and have put me at ease with my considered purchase of older lenses. Maybe down the road I'll want the latest and greatest and spend hundreds of dollars on lenses. But I doubt any advantage a new lense might have is going to make a huge difference to me at my novice level. I figure for under $100 I can "experiment" all I want and not feel that I'm being overwhelmed and have wasted a big investment.

I don't know, autofocus and autoexposure are both pretty big advantages for most people. Given that you can get a 50-200 or 70-300 for well under $200, I'm not sure you'll find it worthwhile to spend $50 on a totally manual zoom lens of questionable optical quality.

I don't know, autofocus and autoexposure are both pretty big advantages for most people. Given that you can get a 50-200 or 70-300 for well under $200, I'm not sure you'll find it worthwhile to spend $50 on a totally manual zoom lens of questionable optical quality.

there has been a lot of discussion and even magazine articles written about using film lenses on digital cameras.

Aside from Manual FOcus vs Auto focus, thich is pretty clear, and whether the lens has an "A" position and aperture controlled by the camera body, there are some other points to consider, which may or may not be relevant to you.

- as already mentioned, newer lenses have ever improving coatings, so the film lenses may not be as good against flare as digital ones.

- Digital lenses do have an additional lens coating on the rear element, to better deal with reflections off the sensor. I personally have not had a big issue with this, but the sensor is much more reflective than film was.

- there have been some reports especially related to wide angle lenses, about excessive vignetting when using film lenses on digital bodies, due to the angle at which light hits the sensor. Digital sensors (and this may be more C-MOS than CCD sensor related, require closer to perpendicular light to hit the sensor. Leica has this issue with their range finder camera, which has the lens much closer to the sensor, aggrivating the problem. Personally I have not seen it, but that only relates to my 43 film lenses, out of the 23million pentax advertised fit the camera

- some film lenses did have shiny parts at the rear of the lens that caused reflections similar to those reported off the rear sensor, I have had this issue as have others in the forum. once identified it can be corrected by flat black brush on paint.

- note that except for pentax's first series of cameras, specifically the *istD, DS and DS2, which supported TTL (through the lens) flash metering, that measured the flash reflected off the sensor for control, as well as P-TTL which measured a preflash using the camera's normal metering system, newer bodies do not support flash metering at all with non A lenses, because the camera needs to know the open aperture of the lens. The preflash is measured knowing the aperture, and predicts the flash duration needed to expose the shot when stopped down to the camera controlled setting, as opposed to actually measuring the flash directly.

- non A lenses show unique and interesting exposure errors as a function of aperture selected, This led to a lot of discussions on the forum over the last 4 years.

on the bright side, there are a lot of excellent film lenses out there, and except for the wide end, actually more variety and options than the current pentax lens line up. Many old lenses are excellent performers when used within their limits (finding these out is part of the fun any way) and there are many exceptional photos posted by forum members using very old lenses. Just look at the Takumar lens club. (Takumars, except the uncoated bayonet lenses of the 1980's went out of production in about 1976)